Quantum gates between non-neighboring spin qubits

ORAL

Abstract

In quantum circuits involving many qubits, we usually need to perform gates such as CNOT between qubits that are not proximal. For spin qubits, this requires intermediate gate operations because the exchange interaction is very short ranged. Here, we consider three quantum dots in a linear array. We explore the effective coupling between the two outer spins mediated by the central spin. By using the central spin as a ``bus", we show how to efficiently perform gates such as CNOT between the outer spins. We find that arbitrary two-qubit gates can be achieved by applying the bus operations repetitively, with additional single-qubit rotations.

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Authors

  • Jianjia Fei

    University of Wisconsin-Madison

  • Yun-Pil Shim

    Department of Physics, University of Wisconsin-Madison, University of Wisconsin-Madison

  • Sangchul Oh

    Department of Physics, University at Buffalo, State University of New York, Department of Physics, University at Buffalo, The State University of New York, University at Buffalo, SUNY

  • Xuedong Hu

    Department of Physics, University at Buffalo, SUNY, University at Buffalo, The State University of New York, Department of Physics, University at Buffalo, State University of New York, Department of Physics, University at Buffalo, The State University of New York, University at Buffalo, SUNY, SUNY at Buffalo

  • Mark Friesen

    Department of Physics, University of Wisconsin-Madison, University of Wisconsin-Madison